NORTHWEST ARKANSAS – Federal regulators pulled the plug on permits issued for two wastewater treatment facilities in northwestern Arkansas that discharge into streams within the Illinois River watershed, heart of a federally designated scenic river in Northeastern Oklahoma.

Arkansas Department of Environmental Quality approved the permits in December despite objections from Oklahoma agencies and Save the Illinois River Inc. U.S. Environmental Protection Agency officials said the upstream state ignored objections and recommendations, issuing permits that differed from draft permits and then failed to submit them for additional review in violation of the Clean Water Act.

"The written recommendations from the state of Oklahoma regarding the NACAS permit were not accepted by the ADEQ, and the EPA finds the reasons for rejecting the recommendations inadequate," EPA Region 6 Water Division Director Charles W. Maguire states in a letter noting the agency's objections. "ADEQ did not accept Oklahoma's recommendations, and the EPA has determined the ADEQ's reason for rejecting the recommendations to be inadequate."

The EPA's rejection of the permits, pursuant to CWA provisions, converts the final permits issued by ADEQ to proposed permits. EPA will issue specific objections by early March to the proposed permits to which ADEQ and other interested parties will have an opportunity to request a public hearing.

If there is no public hearing and ADEQ fails to resubmit a permit that addresses EPA's specific objections, exclusive authority to issue the permits will pass to federal regulators.

Springdale Water Utilities' National Pollutant Discharge Elimination System permit would have retained a 1 mg/L phosphorus cap. The proposed permit authorized a less frequent monitoring standard critics contend was too lenient.

A proposed permit granted for Northwest Arkansas Conservation Authority, a regional wastewater treatment facility that plans to expand capacity, would allow an eventual tenfold increase levels of phosphorus to be released in the wastewater treated there. Arkansas regulators justified the increase through a program that allows nutrient trading offsets.

ADEQ officials, in response to comments submitted by Oklahoma Water Resources Board, confirmed a presumption that the timeframe for total phosphorus concentration limit was changed to reflect revisions to the downstream state's water quality criterion. The phosphorus standard for the Illinois River and two tributaries was changed earlier this year in part to make it a more consistent metric than a shorter averaging period that existed.

Rebecca Veiga Nascimento, an environmental scientist at OWRB who spearheaded revisions to Oklahoma's phosphorus standard for the Illinois River, the Barren Fork and Flint creeks, provided comments to Springdale's draft permit. She states in submitted documents the "six-month average duration ... identified as reasonable and protective" of the Illinois River's beneficial uses may "not seamlessly translate to an effluent limit averaging period for a 24 MGD continuous discharger."

"The monthly averaging period for a permit effluent limit is necessary to more carefully and consistently evaluate effluent quality and permit compliance, which is vital to ensure that Oklahoma's TP water quality standard is attained at the state line," Veiga Nascimento states in OWRB's comments submitted during the permit renewal process. A six-month average period for the effluent limit would allow for considerable variability in TP effluent quality, which may lead to increased contributions of TP to the Illinois River and ongoing failure to attain Oklahoma's WQS."

ADEQ officials state in their response the permitted mass limit for total phosphorus "remains a monthly average limit in accordance with federal regulations." They also cite "a new seven-day average concentration limit," which drew an objection from the director at Springdale Water Utilities, that is expected to "prevent wide fluctuations in phosphorus loading and ensure consistent effluent quality through permit compliance."

STIR President Denise Deason-Toyne, in comments submitted on behalf of the Tahlequah-based citizens coalition, expressed concerns about allowing the facility to continue operating with the existing cap for total phosphorus. The nutrient threatened watershed faces increased risks as the population within the watershed continues to grow.

Water quality degradation within the Illinois River watershed has been attributed to nutrient overloading — particularly phosphorus — in streams. Increased levels of phosphorus triggers algal growth, which depletes dissolved oxygen levels, reduces water quality and threatens aquatic life and habitat.

Deason-Toyne said phosphorus levels at the state line continue to exceed the phosphorus standard established for Oklahoma's scenic rivers despite ongoing efforts to mitigate the problem. A major contributing factor, she said, is the increased flow of treated sewage.

"STIR does not believe the provisions in the draft permit will enhance the protection of the Illinois River in Oklahoma, nor do they feel the proposed permit limitations for phosphorus will help achieve the goal of meeting the 0.037 mg/L phosphorus limit Oklahoma has established," Deason-Toyne states in the organization's comments. “Specifically, STIR objects to the continuation of the 1 mg/L TP (total phosphorus) limit in the permit when the technology exists to reduce it to a limit of 0.1 mg/L or lower.”

Springdale Water Utilities is working on a master plan for its wastewater treatment facility and has the capacity to discharge 24 million gallons of treated sewage a day. It discharges about 200 pounds of phosphorus each day into Spring Creek, which flows into Osage Creek, a tributary of the Illinois River upstream from the Oklahoma border.